Semi Micro Qualitative Analysis Of Simple Inorganic Salt.docx 1s2i5r

SEMI MICRO QUALITATIVE ANALYSIS OF SIMPLE INORGANIC SALT I. PRELIMINARY TEST OBSERVATION

1.

INFERENCE

EXPERIMENT Colour and appearance :

2. Solubility:

A pinch of the salt is shaken with ¾ test tube of water

a. soluble

a. S.S. prepared in water

b. insoluble b. S.S prepared in dil.HCl

II. IDENTIFICATION OF ACID RADICAL Reactions of group-I acid radical OBSERVATION 3.

EXPERIMENT Salt + dil. H2SO4 the gas through lime water.

INFERENCE

Brisk effervescence , a colorless gas is evolved. -

Lime water turns milky.

Carbonate ion (CO3 2) is present and confirmed

Reactions of group-II acid radical 4. Salt + Conc. H2S O4 in a dry test tube.

a. vigorous reaction ,a colorless gas which gives dense white fumes with a glass rod dipped NH4OH shown near the mouth of the T.T b. reddish brown vapours are evolved

a. Chloride ion (Cl- ) is present

b. Bromide ion (Br- ) is present

5.

To the above solution add copper turnings and heat

c. Violet vapours are evolved.

c. Iodide ion is present.

Reddish brown fumes are evolved and the solution turns blue.

nitrate ion (NO3-)is present

Confirmatory test for Cl-

, Br- , I-

(Silver nitrate test) 6.

S.S + dil.HNO3 + AgNO3

a. curdy white ppt soluble in excess of NH4OH b. pale yellow ppt sparingly soluble in excess of NH4OH c. yellow ppt insoluble in excess of NH4OH

-

confirmed

b. Br-

confirmed

a. Cl

c. I-

confirmed

Confirmatory test for Cl- (Chromyl chloride test) 7.

Salt+ potassium dichromate solid + Conc. H2SO4 + heat the gas that is evolved through NaOH solution. The solution is acidified with acetic acid and add lead acetate solution .

8.

Orange red vapours Solution become Yellow

Cl-

confirmed

Yellow ppt

Confirmatory test for NO3- (Brown ring test) S.S+ freshly prepared A brown ring is formed Nitrate ion (NO3-) Fe SO4 solution+ Con. H2SO4 along the sides of the test tube

at the junction of two liquids

confirmed

Reactions of group-III acid radical

OBSERVATION 9.

EXPERIMENT Test for Sulphate: S.S + BaCl2 solution.

A white ppt insoluble in dil.HCl even on heating

INFERENCE SO4

-2

present

Confirmatory test for Sulphate ion 10 .

Lead acetate test: S.S + acetic acid + lead acetate solution.

White ppt

-

SO4 2confirmed

The acid radical was found to be………………………………………………………

III. IDENTIFICATION OF BASIC RADICAL Reactions of group zero basic radical OBSERVATION

INFERENCE

EXPERIMENT 11 .

+

Test for NH4 ion: Salt + NaOH solution + boil

A pungent smelling gas which gives dense white fumes glass rod

+

NH4

ion is present

with a glass rod dipped in Conc.HCl is evolved

Confirmatory test for NH4+ ion 12 .

Nessler’s reagent test: S.S + Nessler’s reagent

Reddish brown ppt

+

NH4

ion is confirmed

Preparation of Salt solution: A concentrated solution of the given salt is prepared by dissolving it in……………………………………………………..

Group-I GroupII S.S + dil.HCl

No ppt Pb+2 absent

S.S + dil.HCl+ H2S(g)

No ppt Cu+2 absent

Group-III

Group separation chart Group-IV Group-V Group-VI

S.S + NH4Cl(s)+ NH4OH (Ex)

S.S + NH4Cl(s)+ NH4OH (Ex) + H2S(g)

S.S + NH4Cl(s)+ NH4OH (Ex) + (NH4)2CO3

No common group reagent

Gelatinous white ppt Al+3 present

Greyish white ppt Zn+2 present Buff ppt Mn+2 present Black ppt

White ppt

Mg+2 may be present

Ba+2 / Sr+2/ Ca+2 present

Ni+2 / Co+2

No ppt Al+3 absent

present No ppt +2

No ppt +2

Zn / Mn / Ni+2 / Co+2

Ba+2 / Sr+2/ Ca+2

absent

absent

Reactions of group-III basic radical OBSERVATION 13 .

EXPERIMENT S.S + NH4OH solution drop by drop to excess.

White gelatinous ppt insoluble in excess.

INFERENCE Al+3 present

Confirmatory test for Al+3 14 .

S.S + NaOH solution drop by drop to excess.

White gelatinous ppt which is soluble in excess NaOH. Al+3 confirmed

To the above solution add NH4Cl(s) and warm.

White gelatinous ppt reappears.

Reactions of group-IV basic radical 15

.

S.S + NaOH solution drop by drop.

a. white ppt soluble in excess

a. Zn+2 present b. Mn+2 present

b. white ppt insoluble in excess of NaOH turns brown on exposure to air

Confirmatory test for Zn +2 16 .

S.S+ potassium Pale green ppt ferrocyanide solution.

Zn+2 confirmed

Confirmatory test for Mn+2 17 .

S.S+ PbO2 (s)+ Con. HNO3 boil, cool and dilute with water

Supernatant solution turns pink in colour

Mn+2 confirmed

Confirmatory test for Co+2 18 .

S.S+ NH4OH solution+ acetic acid

Yellow ppt

Co+2 confirmed

solution + crystals of potassium nitrite. warm.

Confirmatory test for Ni+2 19 .

S.S+ NaOH + few drops of dimethyl glyoxime

Bright red ppt

Ni+2 confirmed

Reactions of group-V basic radical OBSERVATION 20 .

EXPERIMENT S.S+ acetic acid+ potassium chromate solution.

Yellow ppt.

INFERENCE Ba+2 present.

Confirmatory test for Ba+2 21 .

22 .

Salt + Conc.HCl .make a paste with glass rod and then introduced it into the flame. S.S + ammonium Sulphate solution.

Apple green colour is imparted to the flame.

white ppt

Ba+2 confirmed.

Sr+2 present

Confirmatory test for Sr+2 23 .

24 .

Salt + Conc.HCl .make a paste with glass rod and then introduced it into the flame S.S+ NH4OH solution+ ammonium oxalate solution.

Crimson red colour is imparted to the flame

Sr+2 confirmed

White ppt

Ca+2 present

Confirmatory test for Ca+2 25 .

Salt + Conc.HCl .make a paste with

Brick red colour is imparted to the flame

Ca+2 confirmed

glass rod and then introduced it into the flame

Reactions of group-VI basic radical 26 .

S.S + NH4Cl(s)+ NH4OH (Ex) +ammonium phosphate (scratch the inner side of the test tube with a glass rod)

Result:

White crystalline ppt

Mg+2 present and confirmed

The acid radical was found to be………………………….

The basic radical was found to be………………………… The salt is……………………………………………………

-2

SCO3